This invention relates to fluid delivery systems for providing perenteral nutrition, enternal nutrition or other fluids to patients who require infusion of fluids. The invention is particularly related to improvements in such systems which use a disposable fluid delivery set in conjunction with a fluid flow control unit, such as a pump motor set, for supplying such fluids to a patient at a controlled delivery rate.
The assignee of the present invention presently markets an enternal delivery system under the trade name "Kangaroo". The system includes a fluid delivery motor set and a disposable fluid delivery set, which includes a fluid tube, a drip chamber which is arranged to be mounted to recess on the motor set, a mounting member, also arranged to be mounted to a recess on the motor set, an outlet tube connected to the mounting member and a pump tube which connects the drip chamber to the mounting member and engages a motor driven rotor on the motor set to form a peristaltic pump.
In the Kangaroo enteral delivery system the engagement of the pump tube to the rotor controls the flow of fluid to the patient according to the speed of the rotor. In the event the delivery set is not properly mounted to the motor set and the pump tube is not firmly engaged with the rotor, an excess flow of fluid through the set can occur under force of gravity. Improper mounting of the drip chamber is unlikely because of the mechanical configuration of that component and its corresponding recess. Improper placement of the mounting member, e.g. below, above or outside of the receiving recess, is possible if the delivery set is installed on the motor set by an operator who has not received proper instruction in the operation of the system. Instances of such improper installation have been reported.
It is an object of the present invention to provide an interlock system which prevents operation of a fluid delivery system unless the delivery set is properly placed and installed on the flow control unit.